Automatic oil exchanging system



June 3, 1969 R. J. BoNFlLlo AUTOMATIC OIL EXCHANGING SYSTEM Sheet Filed July 24, 1967 INVENTOR. RALPH J. eoNFlLlo yam ATTORNEY R. J. BONFILIO June 3, 1969 AUTOMATIC OIL EXCHANGING SYSTEM Sheet Filed July 24, 1967 NN Nnwu AMV n ,WN

ATTORNEY June 3, 1969 Filed July 24, 1967 R. J. BONFILIO AUTOMATIC OIL EXCHANGING SYSTEM sheet 3 gil- Mn F l G. 4

mmm h F l G.' 5 Iv-WM? INVENTOR. RALPH J. BONFILIC BY 20,2 A

x Mi ff/M ATTORNEY .Fume 3, 969 R. J. BoNFlLlo AUTOMATIC OIL EXCHANGING SYSTEM Sheet Filed July 24, 1967 INJENTOR. RALPH J. BONFILIO ATTORNEY United States Patent O 3,447,636 AUTOMATIC OIL EXCHANGING SYSTEM Ralph J. Bouflo, 1920 Hyde Park Ave., Hyde Park, Mass. 02136 Filed July 24, 1967, Ser. No. 655,453 Int. Cl. F16m 13/02; F01m 1]/00 US. Cl. 184-1.S 8 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to apparatus for automatically exchanging lubricant in the lubricating system of Ian internal combustion engine or the like.

A primary object of the invention is to provide simple and efficient apparatus for withdrawing spent oil from an internal combustion engine and replenishing it with a supply of fresh oil.

A further object of the invention is to provide lubricant exchanging apparatus of the character described having a control system that is operator actuated.

Still another object of the invention is to provide a lubricant-exchanging system for internal com-bustion engines and the like which includes a removeably mounted unit that is adapted to contain a supply of fresh lubricant and also to store spent lubricant withdrawn from the engine.

Still another object of the present invention is to provide an automatic lubricant exchanging system for internal combustion engines and the like which includes a lubricant reservoir in the form of a disposable or reuseable container that is adapted to discharge a supply of fresh lubricant and receive spent lubricant without intermixing thereof.

Other objects and many of the advantages of the present invention will be apparent from the following description, reference being had to the accompanying ,drawings, wherein:

FIG. l is a schematic block diagram of a lubricant exchanging system embodying the present invention;

FIG. 2 is an elevational view, partly in section, showing in greater detail the construction and interconnection of certain of the components of the system of FIG. 1;

FIG. 3 is a sectional view in elevation of the disposable lubricant cartridge that forms part of the reservoir unit of FIG. 4;

FIG. 4 is a sectional view in elevation of the lubricant reservoir unit employed in the system shown in FIG. 2;

FIG. 5 illustrates a second form of lubricant reservoir unit that may be used in place of the preferred embodiment shown in FIG. 4;

FIG. 5A is an elevational View, partly in section, of the expandable bellows unit embodied in the arrangement of FIG. 5;

FIG. 5B is a sectional view in elevation of the cover member employed in the arrangement of FIG. 5;

FIG. 6 is -an elevational view, partly in section, of a third form of lubricant reservoir; and

FIG. 6A illustrates how the lubricant reservoir of FIG. 6 is installed in the system of FIG. 1.

The present invention makes it possible to change the lubricant in an internal combustion engine or the like while the engine is running. The invention is designed so that the operator of a vehicle tted with the lubricant exchanging system, can institute the lubricant exchange operation and kbe assured that the exchange has been completed without having to inspect the engine per se or even remove himself from his seat.

Turning now to FIG. 1, an internal combustion engine of conventional design is illustrated di-agrammatically at 2. The engine may be of the gasoline or diesel type and may be part of an automobile, truck, tractor, bulldozer (or other earth moving equipment), forklift truck, motorized railroad vehicle, marine craft, etc. or may be part of a stationary unit such as a gasoline or diesel type power plant. It is to be understood that the regular lubricating system of the engine comprises a crankcase or oil sump from which oil is supplied to the various moving parts of the engine, and usually includes an oil filter and an oil pump designed to assure circulation to various lubricant-containing chambers of the engine.

For the purposes of this invention, the engine ha-s an outlet port litted with a conduit 4 that connects to one side of an oil lter 6 through a three-way solenoid valve 8 and a conduit 10. The other side of oil filter 6 is connected back to an inlet port in the engine via a conduit 12. The outlet port to which conduit 4 is connected is located at a point in the engine, e.g., the crankcase, at

which the lubricant pressure is higher than at the inlet port. Accordingly, the inlet port of valve 8 (connected to 'conduit 4) is at a higher pressure than its two outlet ports. In its normal deenergized state the valve is open to the outlet port connected to conduit 10 and closed to its other outlet port which is connected by a line 14 to the inlet end of a reserve oil supply unit 16. A small diameter bleeder line 18 connects line 4 to the inlet line 10 of oil filter 6. The outlet end of the reserve oil supply unit 16 is connected by a line 20 to one end of check valve 22. The outlet end of check valve 22 is connected by a line 24 to the inlet port of a pressure responsive valve 26. The outlet port of pressure responsive valve 26 is connected by a line 28 to the inlet port of a temporary fresh oil storage unit 30. The outlet end of the temporary oil storage unit 30 is connected by a line 32 to a return port communicating with the engines lubricating system. It is to be appreciated that line 32 connects with a point in the regular engine lubricating system where the oil pressure is lower than the pressure of the oil leaving the engine via conduit 4. Thus, for example, it could be connected to the oil filter tube or, in the case of an engine having overhead valves, to the chamber defined by the valve lifter cover. Itis further contemplated that, if necessary, a check valve may be inserted in line the temporary oil storage unit 30.

Also forming part of the system of FIG. 1 is a relay 36 that is mechanically coupled to and actuated by pressure responsive valve 26. The mechanical coupling is indicated schematically by the dashed line 38. The relay 36 is connected into a circuit comprising a manuallyoperated control switch 40 that is normally open, the engines battery power supply 42, and the solenoid 8A of valve 8. The manual switch is of the type whose moveable contact is spring biased and will remain closed only so long as the operator holds it closed. Preferably but not necessarily a push-button switch is used. Also forming part of the circuit is an indicator lamp 44 that may be mounted-next to switch 40 in any suitable location, e.g., on the dashboard of a vehicle. As is customary in conventional automotive electric systems employing a battery power supply, the circuit is completed through the Vehicle body as ground.

Turning now to FIG. 2, the pressure responsive valve 26 and the relay 36 are embodied in a single unit 48. The

latter comprises a housing formed of three members 50, 52 and 54 secured together in liuid sealing relation by a plurality of tie bolts 56. The sections 50 and 52 have aligned bores the define a chamber 58 for a valve member 60. The bore in member 50 has a reduced diameter so as to form a seat 62 for valve member 60. The outer end of this same bore is tted with a bushing 64 to which is connected the line 24. The upper end of valve member 60 is provided with a non-conductive stem 66 that extends through a hole in the upper end of member 52 into a relay chamber 68 formed by members 52 and 54. Relay chamber 68 is provided with a vent port 69. The stem 66 is surrounded by a compression spring 70. The latter acts between the upper end wall of chamber 58 and valve member 60 to hold the valve member on its seat. The member S is also provided with a radially extending bore 72 iitted with a bushing 74 to `which is connected the line 28.

The upper end of valve stem 66 is fitted with a contact plate 76 made of a conductive metal. The upper end wall of member 44 is provided with three insulated electrical terminals 78, 80 and 82, each itted with a resilient contact in the form of a conductive compression spring 83. When the valve member `60 moves up against the force of spring 70 to the extent permitted by the length of the -bore in member 52, the plate 76 engages the three contacts and provides electrical connection therebetween. The terminal 78 is connected to the indicator lamp 44. The terminal 80 is connected by a lead wire t0 the positive side of the engines power supply 42. The negative side of this battery is connected to ground. 'Ihe third terminal 82 is connected to ground through the solenoid 8A of valve 8. The switch 40 is connected between the positive side of power supply 42 and the solenoid of valve 12. With this circuit arrangement, closing of the switch 40 by the operator causes the solenoid to be energized by the power supply 42. The solenoid will continue to be energized so long as the switch is held closed. However, engagement of contact plate 76 with the contacts of terminals 80 and 82 will establish a holding circuit for the lamp 44 is completed when the contact plate 76 engages the contacts of terminals 78 and 80.

Still referring to FIG. 2 the temporary fresh oil storage unit 30 comprises a tank 90 having an inlet port 92, an outlet port 94 and vent port 96. The line 28 is connected to inlet port 92. The interior of the tank includes a sleeve 98 that functions as a guide for an inlet valve member 100 and a vent valve member 102. The inlet side of port 92 is bevelled so as to function as a seat for valve member 100 and sleeve 98 is provided with a number of ports 104 which provide communication between the inlet port and the interior Of the tank when valve member 100 is oi of its seat. The vent valve member 102 is attached to a float member 106 made of a suitable lubricant-resistant material that is buoyant in the lubricant that is supplied to tank 90. Vent member 102 is tapered to mate with a tapered valve seat formed around vent port 96. It is to be noted that sleeve 98 is provided with a number of slots 110 which provide fluid communication between lubricant in the tank and the tloat member 106. The oat 106 is coupled to inlet valve member 100 by a exible tether 111.

The outlet port 94 of tank 90 is provided with a tubular extension 112 that forms a guide for an outlet valve member 114. The bottom end of valve member 114 is tapered to mate with a tapered valve seat surrounding the inner end of outlet port 94. Member 112 has a number of ports 116 that permit escape of lubricant to discharge port 94 when valve member 114 is lifted olf of its seat. Tank 90 also has a second smaller outlet which is fitted with a spring biased valve 117. The latter is normally biased to the closed position but will open under uid pressure to connect tank 90 with conduit 32. Valve members 100 and 114 are pivotally connected to .the

opposite ends of a lever 118 that is pivotally connected to a post 120 attached to the bottom wall of the tank. The pivot pin connecting lever 1.18 to valve member 114 is located in a slot in the valve .member so as to provide a lost motion connection. A tension spring 121 links valve member 114 and the end of lever 118. A spring member 112 attached to the vertical port 118 bears on lever .118 so as to urge valve member 100 into closed position with respect to inlet port 92 and valve member 114 into open position with respect to outlet port 94. In the absence of any lubricant in the tank the vent port 94. In the absence of any lubricant in the tank the vent portion 96 will be open, valve members 100 and 117 are closed, and valve member 114 is open. When lubricant iluid is introduced into the tank via port 92 the oat 106 will move up according -to the level of the lu bricant so that eventually valve member 102 will close oit vent hole 96. Valve member 100 will remain in closed position until such time as lubricant is delivered to inlet port 92 via line 28. The incoming lubricant lwill be under suflicient pressure to lift valve member 100 off of its seat. Because of the connection therebetween provided by lever 11,-8, upward movement of valve member 100 will cause valve member 114 to close olf the outlet port 94. The latter will be closed by valve member 114 as long as lubricant continues to be delivered to the tank via line 28. Float member 106 will rise with the level of lubricant in the tank and eventually will cause valve member 102 to close ofi the vent port. However, the oat member is designed so that closing of the vent port does not occur until the tank has received substantially all, e.g. -90f%, of the fresh lubricant supplied by the fresh oil supply cartridge 16. Closing of the vent port causes a backpressure to be created in the tank. This back pressure causes valve 117 to open so that oil will start to flow into conduit 32 at a modest rate. Oil continues to leave 'tank 90 solely via valve 117 until no more oil is delivered via conduit 28, whereupon spring 122 will force valve member back onto its seat and reopen the outlet port 94. The tether 111 causes the vent valve member 102 to open the vent port 96 when valve member 100 moves back onto its seat. When this occurs the lubricant in tank gg will discharge into conduit 32 at a rapid rate via port Turning now to FIGS. 2, 3, and 4, the reserve oil supply unit 16 comprises a housing 126 fitted with a removable cover 128. The latter is provided with a pair of ears adapted to receive tie-down bolts 132 that are pivotally secured to lugs 134 formed on the exterior of housing 126. -Nuts 136 screwed onto bolts 132 act to secure the cover to the housing. The cover 128 is provided with a central opening in which is secured a bushing 138. Mounted in and secured by bushing 138 is a rigid sleeve 140 that forms an extension of a pipe line 14A. In this connection it is to be appreciated that the pipe line 14A is a flexible conduit. The other pipe lines in the system also may comprise llexible conduit. It is to be noted further that pipe line 14A forms an extension of pipe line 14 and is connected thereto by a check valve 142 arranged to prevent backflow to solenoid valve 8. Sleeve 140 extends through the cover for a short distance and its ilnner end is provided with a number of small openings The bottom end of housing 126 is provided with a discharge opening in which is secured another bushing 146 having a tubular extension 148 whose inner end is provided with a number of holes 150 similar to holes 144. The inlet end of check valve 22 is screwed into the outer end of bushing 146.

Check valve 22 (and also check valve 142) may take any one of several conventional forms. Preferably, however, it is of the type that comprises a spherical valve member 152 that is urged against an appropriate valve seat at its inlet end by means of a compression spring 154. It is to be understood that the valve member 152 is normally in closed position and opens only under the pressure of lubricant introduced into its inlet port by way of the tubular extension 148.

The housing 126 contains a removeable reservoir oil cartridge 158. As shown in FIG. 3, this cartridge comprises a rigid cylindrical case 160 made of metal or plastic which is closed oil" at its top and bottom ends by wall members 160 and 162. The upper wall member 160 is provided at its center with a frusto-conical depression 164 having one or more ports 166. Attached to upper wall member 160 is a cup-shaped member 168 having an end opening in which is secured a resilient collar 170, preferably made of an oil resistant rubber. The inner end of collar 170 is closed off by a at valve member 172 which is urged in closed position by a compression spring 174.

The bottom end of case 160 is provided with a similar frusto-conical depression 176 having ports 178 similar to ports 166. A second cup-shaped member 180 is attached to the bottom end wall 162. This cup-shaped member 180 is similar to member 168, including a second resilient collar 182 which is closed off by a valve member 184 that is inuenced by a compression spring 186.

The case 160 contains a fresh supply of lubricant 188 and a piston 190 which is provided with are ring seals 192 at its periphery. With a full supply of fresh lubricant the piston 190 engages and is stopped by the frusto-conical section 64 of the upper end wall 160. Although not shown, the cartridge of FIG. 3 may include a guide shaft for piston 190 extending between and anchored to the end walls of case 160. The piston would have a center hole sized so that the piston would be able to slide in the shaft. This center hole in piston 190 would, of course, have a seal to prevent passage of lubricant from one side to the other of the piston.

Installation of cartridge 158 in the manner shown in FIG. 4 is straightforward and requires no special tools. With cover 128 removed, the cartridge is dropped into housing 126 and pressed down over the tubular extension 148 so that the latter will penetrate the collar 182 and force valve member 184 off of its seat. The cartridge is forced down far enough for the openings 150 to be exposed to the interior of cup member 180, whereby communication is established between the supply of fresh lubricant 188 and the inlet port of check valve 22. Then cover 128 is applied so that sleeve 140 presses valve member 172 into open position, thereby providing communication between the sleeve 140 and the space 194 between end wall member 160 and piston 190. -It is to be appreciated that the normal pressure of the fresh lubricant 188 due to the influence of gravity is insutlicent to open the check valve 22.

Operation of the system of FIGS. 1-4 will now be described. Assume that the engine 2 is running and the operator desires to replace the oil in the engine with the fresh supply contained in the cartridge 158. The operator closes switch 40 and holds it closed until lamp 44 is illuminated. Closing switch 40 immediately causes the valve solenoid 8A to be energized whereupon the valve shifts from its normal position connecting lines 4 and 10 to a new position wherein it connects lines 4 and 14. AS soon as this occurs oil commences to iiow from the engine via line 14 into the upper end of the cartridge 158. This incoming oil is under greater pressure than the oil in the cartridge 158 and, therefore, it forces the piston 190 downward. This downward movement of piston 190 `forces the fresh lubricant 188 out of the cartridge to the pressure responsive unit 48 comprising valve 26 and relay 36. The fresh Oil entering the pressure responsive unit 48 forces the valve member 60 off of its seat and passes through line 28 to tank 90. The flowing oil raises valve member high enough to cause plate 76 to engage the contact of terminals 78, 80 and 82. At this point lamp 44 will go on and the operator may allow switch 40 to reopen. However, so long as oil continues to be pumped through the lines 24 and 28 the plate 76 will continue to close the circuit between terminal on the one hand and terminals 78 and 82 on the other hand, so that lamp 44 and the solenoid of valve 8 will remain energized. The spring contacts 83 assure that the circuit will be maintained if plate 76 tends to vibrate under uctuating oil pressure. The fresh oil will continue to flow into the temporary storage tank until the piston 190 engages the frustoconical portion 176 of case 160'. When this occurs, the valve member 60 will rcseat itself and this in turn will cause lamp 44 to go out and the valve solenoid to be deenergized. The latter action causes the valve 8 to return to its original position connecting conduit 4 to conduit 10. Termination of the ow of fresh oil to tank 90 will cause valve member to close and valve member 114 t0 open, thereby permitting rapid discharge of oil from tank 90 through line 32 into the engine. Thereafter it will circulate in the normal way through the engines lubricating system including oil filter 6. The spent oil remains in the cartridge which at a later time is replaced with a new cartridge containing another supply of fresh oil.

It is believed to be apparent that temporarily storing the fresh oil in tank 90 makes it possible to drain the engine of spent oil before the fresh oil is introduced, so that there is no substantial intermingling of spent oil and fresh oil. In this connection it is to be noted that the exchange of oil takes place within two-three minutes and in the interval between removal of spent oil and delivery of fresh oil, the engine is lubricated by the small amount of oil that is in the lter 6. In most cases this is suiicient. Otherwise bleeder line 18 is required to make certain that there is maintained in the engine a small supply of lubricant sufiicient to prevent injury to pistons, crank shafts, connecting rods etc. during the oil changing operation. It is to be noted that the oil introduced via bleeder line 18 need not be great and is controlled by the diameter of line 18.

FIGS. 5, 5A and 5B illustrate a further modification of the invention.

The apparatus shown in these figures is intended as a replacement lfor the reservoir oil supply unit Shown in FIGS. 2 and 4. -In this case the reservoir oil supply unit comprises a housing 200` that is open at its top end and is provided with a threaded outlet port 202 at its bottom end for connection (by means of a bushing or nipple) to the check valve 22. The housing 200 is provided with a pair of lugs 204 to which are pivotally secured threaded members 206. These threaded members 206, together with nuts 208, serve to secure to the housing a cover member 210. The latter is provided with suitable apertures for threaded members 206. The center of cover member 210 is provided with a hole in Iwhich is mounted a bushing 212. Secured in this bushing 212 is a rigid sleeve 214 that forms an extension of the line 14. Sleeve 214 is made of metal and its bottom end is cut on an angle so as to form a sharp cutting edge 216.

Associated with the housing and supported therein is an extendible member 218. Referring now to FIG. 5A, member 218 is formed with a stiff plate 220 tted with a rubber gasket 222 at its periphery. At its center plate 220 is provided with a hole in which is secured a resilient sleeve 24 that ts in and makes a iluid tight with the center hole of plate 220. As shown in FIG. 5A, the upper end of sleeve 224 is sealed olf by plastic or metal disc 226 that is rupturable. For example, the disc 226 may be made of aluminum. Attached to the underside of plate 220 is an expandable bellows 230, having a stiff bottom end wall 232. The bellows is formed with an open top end and its upper edge is secured to plate 220. Bellows 230 is made of a flexible material that is resistant to lubricant and is strong enough so as to contain a supply of lubricant when expanded. Thus the bellows 230 could be made out of plastic, oil resistant rubber or a rubber or plastic-impregnated paper. The bellows is normally collapsed as shown in FIGS. and 5A. On its upper side the plate 220 is provided with a pair of bracket members 234 that pivotally support a bail 236. The latter normally lies flat against plate 220 when member 218 is installed in the manner shown in FIG. 5. It is to be noted that the rupturable disc 226 is provided merely to prevent air from entering the bellows so that it will tend to remain collapsed pending installation in housing 200.

In practice a supply of fresh oil is poured into housing 200, filling it to just about the level of the bottom end of member 218 when positioned as shown in FIG. 5. Thereafter member 218 is inserted into the housing so that gasket 222 resets on the peripheral flange 238 formed around the upper end of the housing. Bellows 230 is sized so as to make a snug fit with the interior side surface of housing 200. Then cover Amember 210 is placed over the housing and forced down so that the sharp edge 216 of sleeve 124 penetrates and ruptures disc 226. The cover is secured in place by nuts 208 and threaded members 206.

The mode of operation of the system of FIG. l using the arrangement of FIG. 5 is essentially the same as it is using the arrangement of FIGS. 2-4. The fresh lubricant will remain in the housing 200 until the solenoid valve is energized, whereupon spent oil lwill pass through the line 14 and sleeves 214 and 224 into the bellows 230. The incoming spent oil will cause expansion of bellows 230 so that its bottom wall 232 will in turn force fresh oil out of the housing 200 through port 202 into line 24. At the end of the oil exchanging operation the bellows 230 will be completely filled with spent oil. Thereafter member 218 can be removed and spent lubricant discarded simply by detaching the cover 210 and lifting member 218 out of the housing by means of the bail 236.

FIGS. 6 and 6A show a further modication of the invention wherein the entire reservoir oil supply unit is disposable. This fully disposable unit comprises a rigid cylindrical case 240 having upper and lower end walls 242 and 244. Rivotally secured at 246 to the upper end of the case is a bail 248. Secured in a hole in the center of upper end wall 242 is a sleeve 250` made of a resilient material, e.g., rubber. Sleeve 250 is closed off by a rupturable disc 252 made of a suitable material such as aluminum or a plastic. The bottom wall member is provided with a similar sleeve 254 having a similar rupturable disc 256. Welded to the inner side of the bottom end wall is a cup-shaped member 285 provided with a number of ports 260. Also disposed within the case 240 is bellows element 262. This bellows element has a bottom end wall 264. The upper end of this bellows element has a second end wall 266 that is cemented to the end wall 242 of the case. The center of this end wall 266 has an aperture concentric with sleeve 250. As made and ready for installation, the disposable reservoir unit is filled with fresh lubricant 268 and the bellows is collapsed as shown in FIG. 6. To accommodate this unit in place of the unit of FIG. 5, sleeve 214 is further provided with a rubber gasket 270A which is attached a short distance above its sharp end 216. Thus when the sleeve 214 is made to penetrate disc 252 so as to provide communication between the line 14 and the interior of the bellows 262, gasket 270A will make a fluid tight connection with sleeve 250 as shown in FIG. 6A. The bottom end of the case 240 is secured to a sleeve 272 identical to sleeve 214 but secured to the inlet end of check valve 22 shown in FIG. 4. The disc 256 is ruptured by the upper end of sleeve 214. Another rubber gasket 270B on sleeve 272 is adapted to make a fluid tight connection with sleeve 254. Other means (not shown) may be used to support the case 240 so that it is rigid and will not move from side to side.

Operation of the system of FIG. 1 using the embodiment of FIG. 6 is essentially the same as that described above. When the solenoid valve is energized, spent oil removed from the engine enters bellows 262 via line 14 and sleeves 214 and 250. The incoming spent oil causes the bellows to expand, and this expansion forces the fresh oil 268 out of the case 240 via sleeve 272 into line 24. The bellows will expand to the limit afforded by its own length and/ or the length of the case 240, depending on which is shorter.

In practice it is preferred that the bellows expand the full length of case 240. When -fully expanded and filled with spent oil 276 the bottom end 264 of the bellows will rest on the bottom end lwall 244 of the case and on member 258. In this connection it is to be noted that the latter elevates the center portion of the bottom end of the bellows so that it cannot be injured by the sharp pointed end of the sleeve 272.

The unit of FIGS. 6 and 6A offers advantages similar to those of the embodiment of FIGS. 3 and 4. It is easy to install and replace and, because its construction is relatively simple, it is disposable. On the other hand it is to be noted that the spent oil in the bellows could be emptied out and the bellows returned to its collapsed lform by refilling the case with fresh lubricant. In the event of such reuse, new rupturable plugs 252 and 256 would be installed. Like the member of 218 of FIG. 5 the unit of FIG. 6 offers the advantage that it can be lifted out by means of its bail and taken away without spilling its contents.

It is believed to be apparent that many variations of the invention are possible in the light of the foregoing description. The reservoir oil unit construction is susceptible of many modifications and changes. Similarly other components employed in the system may be rearranged or modified. Thus, for example, it is not necessary for the pressure responsive valve and the valve actuated relay to be constructed as the single unt 48. Furthermore the electrical circuit could be changed so that the relay would be actuated by a timer rather than oil pressure. Accordingly, it is to be understood that within the scope of the appended claims the invention may be practiced other than described, illustrated, or suggested herein.

I claim:

1. In combination with an engine having a lubricating system including a reservoir chamber containing lubricating oil for said system, apparatus for replacing used lubricating oil in said system -with a supply of fresh lubricating oil, said apparatus comprising a container filled with a supply of fresh lubricating oil, conduit means for withdrawing used lubricating oil from said reservoir chamber and delivering it to said container under pressure, a valve in said conduit means normally preventing flow of used lubricating oil to said container, said valve being operable to permit flow of used lubricating oil to said container, displaceable means in said container for forcing fresh lubricating oil out of said container as used lubricating oil is delivered thereto by said conduit means, said displaceable means being constructed so as to prevent intermingling of fresh and used lubricating oil, means connected to said container for receiving fresh lubricating oil therefrom and introducing it into said lubricating system after substantially all of the used oil has been withdrawn from said reservoir chamber, and valve operating means adapted to open said valve so as to permit delivery of used lubricating oil to said container from said reservoir chamber and to automatically close said valve after substantially all of said used lubricating oil has been withdrawn from said reservoir chamber.

2. The combination of claim 1 wherein said valve is a solenoid valve and said valve operating means comprises a control circuit for energizing and deenergizing the solenoid of said Valve.

3. The combination of claim 2 wherein said control circuit includes a manually operated switch that is normally open and is connected so as to complete said control circuit when it is closed.

4. The combination of claim 3 further including means for establishing a holding circuit for said solenoid after said switch has reopened provided that fresh oil is being 9 10 forced out of said container at the time said switch re- References Cited opens.

5. The combination of claim 4 further including means UNITED STATES PATENTS for interrupting said holding circuit after ow of fresh 2,644,430 7/1953 Lang 184 15 oil from said container has terminated. 5 219461328 7/1960 Mett'etal 123- 196 6. The combination of claim 1 wherein said container 32161527 11/1965 LeWlS 184-15 is a replaceable cartridge. I.

7. The combination of claim 1 wherein said displace- LAVERNE D' GEIGER P'lmary Emmmer' able means is a piston. EDWARD I. EARLS, Assistant Examiner.

8. The combination of claim 1 wherein said displace- 10 able means comprises a bellows adapted to be lled with US Cl- X-R.

Said used Oil. 123-196 

